~ jan JJsPond.us wrote:

I never said a filter was necessary to remove algae or that plants don't
work. I said plants alone are not sufficient.


This hasn't been my experience.

It might be. You don't have a separate filter but maybe you have enough
surface area with all your plants that you don't need a filter.


I guess I'll have to go back and re-read, maybe he's changed something
since I read it a few years old. What I remember is the relationships of
the different algaes competing again each other. Can you remember where in
particular he says plants alone don't work?

Check this page: http://www.koiclubsandiego.org/GRENH2O.html It
describes how ponds are clear because something kills the algae and not
that there's some sort of competition and the algae loses. As he says,

"THERE IS SOME COMPONENT IN CLEAR ESTABLISHED POND WATER THAT IS TOXIC
TO THE BLOOM ALGAE."

Also,

"This theory is exactly the opposite of competition effects. Remember
the myths based on Liebig's Law involve the removal or reduction of some
factor, such as nutrients, or light, required by the bloom algae. This
theory states that something is naturally ADDED to the water that kills
the bloom algae."

He says the added algicide is a byproduct of some type of bacteria (not
the kind that removes ammonia) that feeds on dead algae cells. If this
is true then, in your pond without a filter, it's not a lot of plants
sucking up nutrients that kill algae but maybe a lot of plant roots or
rocks or who knows what that provide enough surface area for the
bacteria to live. So in your case plants alone work but they're not
working for the reason many people think they do. I also suspect you
have a *lot* of plants in the filterless pond. Or at least, compared to
many people that add half a dozen plants to a 1000 gallon pond in hopes
of clearing the algae.

Sure, plants alone won't work on a well stock koi pond, but they work fine
in a very low stock goldfish pond or watergarden with just minnows. IME

I wonder how many plants and how many fish. I had 6 small fish in 1300
gallons and going from 10 to 20 plants did nothing for the water. It
would be helpful if we could quantify some of these ideas.

My reason for bringing any of this up is that a year ago I was getting
frustrated trying any of the many ideas I've seen and not getting anywhere.

Matt